What was the reason for the anxiety of Paul's mother as he grew older?

As it can be implied from the story, The Rocking-horse Winner, Paul was an autistic child who also suffered Oedipus-complex. The story pictures a very young Paul who is at the threshold of teenage and is very eager to fight the sounds that keep whispering in his house that “there must be more money He was desperate to bring happiness to his mother through money and desired to replace his father in her life. As Paul grew impatient and betted on racing horses to earn money by means of gambling. Hester, realised that her son was indulging too much in horse racing and asked the gardener and her brother to keep him away from it. She realised how tensed Paul had grown. Yet she knew not that the worry that had been eating and consuming him up was of his mother. Eager to win, Paul lost, and lost again. It was before Derby, he grew worried to earn for his mother and prove his luck to her. She was worried so much that she left the party in the middle to return to her son to see him safe and healthy. However, it was the last time she saw her son in senses.